The present invention relates generally to vacuum cleaners, and more specifically to the end assemblies that rotatably mount a brushroll in a vacuum cleaner.
An example of brushroll mounting assemblies is disclosed in U.S. Pat. No. 5,272,785 dated Dec. 18, 1993, the disclosure of which is incorporated herein by reference. The disclosed mounting assemblies include stub shafts which are fixed in the ends of the spindle, bearings which have their inner races pressed fitted on the projecting ends of the stub shafts, and outer end members, e.g. end caps, that receive the outer races of the bearings and serve as a means for mounting the brushroll in the mouth of the vacuum cleaner nozzle.
Certain prior art brushrolls include metal ferrules that embrace the outer ends of the spindle. In a typical construction, the stub shafts extend through center openings of the ferrules into the spindle ends. The metal ferrules can have expanded end openings that receive projecting portions of the end caps in order to guard against threads and dirt from entering the bearings.
The present invention features a skirted, one piece plastic ferrule that fits into each end of the spindle and receives the stub shaft of the end assembly. The one-piece ferrule includes a peripheral skirt that embraces the end portion of the spindle, a hollow pin which is pressed into the end of the spindle and receives the stub shaft, and a web connecting the pin and skirt.
In a disclosed embodiment, each end of the spindle has a hole in which the ferrule pin is pressed, a countersunk mouth, and an outer, axially extending lip around the mouth of the hole. The ferrule web has a radial bottom wall confronting the bottom of the spindle mouth, an axial wall fitted against the inside of the spindle lip, and a second radial wall that connects the skirt and axial wall. The skirt and axial wall of the ferrule are radially spaced apart to define an annular recess or cavity that receives the spindle lip.
The described ferrule of the invention provides a number of important advantages. The plastic skirts around the end portions of the spindle can be drilled with a conventional wood drill to provide tuft holes very near the ends of the spindle. The skirt prevents cracking or splitting of the spindle ends when they are drilled. Angled tufts extend through the skirts beyond the ends of the spindle in order to widen the normal brush cleaning path. The angled tufts at the ends of the spindle improve edge cleaning and overall cleaning characteristics of the brushroll. The metal ferrules of the prior art cannot be drilled with conventional wood drills to permit tufting at the ends of the spindle. Thus, a brushroll with metal ferrules at its ends necessarily has a narrower cleaning path than achieved with the ferrule of the present invention.
Moisture changes in wooden spindles can cause shrinking and swelling of the wood. In many conventional constructions, swelling can result in the pins or stub shafts which mount the bearings from loosening in the holes of the spindle, thereby causing brushroll rattle and general unsatisfactory operation. The skirted ferrule of the present invention avoids this difficulty. As the spindle swells against the ferrule skirt, the wood is compressed to maintain a firm grip on the ferrule pin. Metal ferrules address the same problem, but, as described above cannot achieve the same wide cleaning path and edge cleaning capability that characterize the present invention.
Another feature of the invention is that it creates a lower cost product compared to the metal ferrule and multi-part constructions of the prior art. The ferrule including the hollow pin, skirt and connecting web can be injection molded as a one piece part that is easily assembled with the spindle.
Still other features, advantages and a fuller understanding of the invention will become apparent to those skilled in the art from the following description of the preferred embodiment of the invention and the accompanying drawings.